The present invention relates to a solar cell module which is mounted on the roof of a house, etc. for photovoltaic power generation.
Photovoltaic power generation for converting light energy into electrical energy by using a photoelectric conversion effect has been widely used as means for obtaining clean energy. Besides, with an improvement in the photoelectric conversion efficiency of solar cells, a photovoltaic power generation system using a large number of solar cell modules is being operated even in private houses.
FIG. 1 is a view showing the outside structure of a general solar cell module, and FIG. 2 is a cross sectional view of a conventional solar cell module cut along the X-X line of FIG. 1. In these figures, the numeral 7 denotes a rectangular frame body made of aluminum. There is a recessed section in the upper half of the frame body 7, and a glass plate 1 and a protective film 50 are mounted in this upper recessed section at a suitable distance therebetween through a filler 6 made from silicone. The protective film 50 comprises weatherproof sheets 50b made, for example, of PVF (polyvinyl fluoride) and sandwiching an Al foil 50a, and has weatherproof properties, particularly high moisture-proof properties. A plurality of solar cells 2 are sealed between the glass plate 1 and the protective film 50 by a sealing resin 3 made from EVA (ethylene vinyl acetate). In some cases, each solar cell has a wiring tab protrusion 2a. 
The solar cell module comprising the moisture-proof protective film 50 including the Al foil 50a has an insulation problem for the following reasons. Specifically, there are cases where the internal solar cell 2 or its wiring tab protrusion 2a comes into contact with the Al foil 50a of the protective film 50 (the part A in FIG. 2) and a short circuit occurs between the Al foil 50a of the protective film 50 and the frame body 7 (the parts B and C in FIG. 2) particularly when it is raining, and consequently the insulating characteristics deteriorate.